Surgical nail extractor

ABSTRACT

An extractor for removing a broken portion of an intramedullary nail includes an inner rod member and an outer concentric tubular member, each having a pair of axially extending fingers at one end. The fingers are arranged in respective pairs and each finger of such pair includes a pin having a portion extending beyond the inner surface of the finger, with the projecting portions of the pins axially and circumferentially converging with respect to each other. The other end of the inner member is secured to a drum rotatably and slidably received within a housing secured to the other end of the outer member. Fixed handles on the housing have their inner ends extending into an annular groove of the drum to limit axial movement of the drum and inner member relative to the housing and outer member. A manually rotatable handle on the housing has its inner end engaging the wall of an axially extending groove in the drum to rotate the drum and housing and the inner and outer members relative to each other and bring the projecting portions of the pins into clamping engagement with a land of the cruciform cross sectionally shaped nail. The inner member also includes an end anvil which can be used to shift the broken portion of the nail within the medulla to free the nail for easier removal. A handle assembly secured to the drum permits attachment of conventional instruments which apply intermittent axial driving forces to the inner member.

United States Patent [541 SURGICAL NAIL EXTRACTOR 4 Claims, 7 DrawingFigs.

[52] US. Cl 128/83, 128/92 EC, 279/1 T, 227/63 [5 l] Int. Cl. A61! 5/04[50] Field of Search..... 128/83, 92

EC, 92, 92 E; 81/104, 3.05, 53.2; 29/278, 28!; 279/] T, 29, 30; 227/63[56] References Cited UNITED STATES PATENTS 2,579,438 l2/l95l Longfellow145/52 OTHER REFERENCES The British Medical Journal, June 27, 1936 page1304, copy in group 330 128/92 Primary Examiner- Richard A. GaudetAssistant Examiner-J. Yasko Anomeysw. E. Finken and Herbert FurmanABSTRACT: An extractor for removing a broken portion of anintramedullary nail includes an inner rod member and an outer concentrictubular member, each having a pair of axially extending fingers at oneend. The fingers are arranged in respective pairs and each finger ofsuch pair includes a pin having a portion extending beyond the innersurface of the finger, with the projecting portions of the pins axiallyand circumferentially converging with respect to each other. The otherend of the inner member is secured to a drum rotatably and slidablyreceived within a housing secured to the other end of the outer member.Fixed handles on the housing have their inner ends extending into anannular groove of the drum to limit axial movement of the drum and innermember relative to the housing and outer member. A manually rotatablehandle on the housing has its inner end engaging the wall of an axiallyextending groove in the drum to rotate the drum and housing and theinner and outer members relative to each other and bring the projectingportions of the pins into clamping engagement with a land of thecruciform cross sectionally shaped nail. The inner member also includesan end anvil which can be used to shift the broken portion of the nailwithin the medulla to free the nail for easier removal. A handleassembly secured to the drum permits attachment of conventionalinstruments which apply intermittent axial driving forces to the innermember.

PATENTED um 4 l97l 3 2,35

SHEET 1 OF 2 1 2/02 ART Z6 V i 1 m ATTORNEY PATENTEUnEcMBn 3.628335SHEET 2 OF 2 A TVTOR N E Y SURGICAL NAIL EXTRACT OR This inventionrelates to medical instruments and more particularly to an extractor forremoving a broken portion of an intramedullary nail from within themedulla of a bone.

lntramedullary nails are used to strengthen fractured bones while thebones heal. Ordinarily such nails remain in place for years without anyproblems. However, occasionally the nail will fracture and must beremoved. Prior to our invention, it was impossible to remove both brokenportions of the nail through the same opening in one end of the bone.

Generally, the intramedullary nail is of cruciform cross section andincludes a central part having smooth edged lands, an intermediatecylindrical part extending to each side of the central part and havingaxially and radially inwardly tapering lands continuing the lands of thecentral part and provided with sharp-edged ribs, and ascrew-threaded endpart extending from each intermediate part. The nail is inserted withinthe bone medulla with the central part located across the fracture, withthe edges of the central part lands and certain of the ribs engaging thewall of the medulla to retain the nail in place, and with one of thescrew-threaded end parts extending into one bone end or cartilage.

Once an opening has been formed in the end of the bone and the brokenportion of the nail adjacent this opening removed, the extractor of thisinvention permits ready removal of the remote broken portion of the nailthrough the same opening in the end of the bone. Thus no additionalentrances to the bone medulla are required to permit removal of theremote broken portion of the nail.

In the preferred embodiment of the invention, the extractor includesinner and outer concentric tubular members which are both rotatable andaxially reciprocable relative to each other. The free end of each memberis provided with a pair of fingers, with one finger of one member beingrespective to one finger of the other member so that the fingers arearranged in respective pairs. The other end of the inner member issecured to a drum which is rotatable and axially reciprocable within anouter cylindrical housing having a closed end wall secured to the otherend of the outer member. The drum includes a handle extending outwardlyof the open end wall of the housing so that the drum and the innermember may be axially shifted and rotated relative to the outer memberand housing. The housing mounts a threaded member which is engageablewith a radially facing axially extending surface of the drum to rotatethe inner and outer members relative to each other and thereby move therespective pairs of fingers toward each other.

When a broken intramedullary nail is to be removed, a conventionalinstrument, such as a Reynolds Driver having a threaded socket, isinserted through the opening in one end of the bone and into the bonemedulla into threaded engagement with the threaded end part of thebroken portion of the nail adjacent the opening. Thereafter, bymanipulation of the ring weight of the instrument, this broken portionis removed, with the ribs on the intermediate part breaching the medullawall during removal.

Thereafter the extractor of this invention is inserted into the medulla,with the fingers of the inner member axially extended with respect tothe fingers of the outer member. The fingers of the inner member arethen positioned with the aid of a fluoroscope or otherwise within thebone marrow in one diagonally opposite pair of valleys between the landsof the nail. The inner member further includes an end anvil or abutmentwhich is then moved into engagement with the fractured end of the remotebroken portion. A conventional instrument, such as a Reynolds Driver, isthen attached to the drum han dle and the remote broken portion of thenail shifted axially within the medulla so that the ribs of theintermediate part of this broken portion broach the medulla wall andfree the broken portion from engagement therewith. Since the drum andinner member are shiftable as a unit relative to the housing and outermember, the latter remains relatively stationary as the instrument isused.

The inner member is then axially retracted with respect to the outermember and rotated approximately to position the fingers of the innermember in general axial alignment with the other diagonally oppositepair of valleys between the lands of the broken portion of the nail. Theinner member is then axially extended with respect to the outer memberto position the fingers in the bone marrow between the other pair ofvalleys. The outer member is then shifted axially of the inner member toposition the fingers of the outer member in the cavities in the one pairof valleys made by the fingers of the inner member. Each finger of eachrespective pair includes an axially extending gripping member ofhardened steel, with these gripping members converging toward each othercircurnferentially and axially outwardly of the medulla or axiallyopposite the direction in which the extractor is inserted. The threadedmember on the housing is then rotated to rotate the inner and outermembers toward each other and cause the gripping members to bite intothe opposite surfaces of the lands of the remote broken portion of thenail. Thereafier a conventional instrument, such as a Reynold's Driver,is again attached to the handle of the inner member and, by use of thering weight of the instrument, the extractor and the remote brokenportion of the intramedullary nail are removed from the medulla. A newintramedullary nail can thereafter be readily inserted if necessary.

The primary object of this invention is to provide an extractor forremoving a broken portion of an intramedullary nail from within themedulla of the bone. Another object of this invention is to provide suchan extractor which can be inserted into the medulla and thereafter movedinto gripping engagement with the broken portion of the nail to removethis broken portion through an opening to the medulla in an end of thebone remote from the broken portion. A further feature of this inventionis that the extractor permits both portions of the intramedullary nailto be readily removed through only one opening to the medulla. Yetanother feature of this invention is that the extractor includes a pairof telescopic and rotatable members, each of which includes grippingfinger means at one end thereof which are arranged in respective pairsfor gripping engagement with the arms or lands of the cruciform part ofthe nail. Yet a further feature of this invention is that the membersare concentric and that the inner member includes an anvil or anabutment which may be engaged with the end of the broken portion of thenail to move the broken portion relative to the medulla and broach themedulla wall to permit easier removal of this broken portion.

These and other objects and features of this invention will be readilyapparent from the following specification and drawings wherein:

FIG. 1 is a view partially in section showing a broken intramedullarynail within the cavity of a fractured femur and a conventionalinstrument attached to the one broken portion of the nail adjacent anopening in one end of the bone for removing this one broken portionthrough the opening;

FIG. 2 is a view similar to FIG. I and showing the extractor of thisinvention grippingly engaged with the other broken portion of the nailremote from the opening to remove this other broken portion through theopening;

FIG. 3 is an enlarged view taken on line 3-3 of FIG. 1 showing the crosssection of the cruciform part of the intramedullary nail;

FIG. 4 is an enlarged sectional view taken generally on the planeindicated by line 4-4 of FIG. 2;

FIG. 5 is an enlarged perspective view of a portion of a finger commonto the inner and outer members;

FIG. 6 is an enlarged broken away view of a portion of FIG. 2; and

FIG. 7 is a sectional view taken generally along the plane indicated byline 7-7 of FIG. 6.

FIGS 1, 2 and 4 of the drawing show a portion of a fractured human femurdesignated generally 10 and including a medulla 12 which is normallyfilled with bone marrow l4. Positioned within the cavity 12 is aconventional intramedullary nail 16 of cruciform cross section havingpairs of oppositely extending arms or lands 18 and 20. The ribs of thecenter part 22 of the nail are smooth edged, FIG. 3, while the ribs ofthe intermediate parts 24 of the nail taper oppositely of each othertoward a respective end of the nail and are provided with sharp-edgedcircumferentially aligned ribs 26. The tapered end parts 28 of the nailare screw threaded. As shown in FIG. 1, the center part 22 of the nailis normally positioned across the fracture in the femur l0. Normallysuch nails in adults remain in place for life after insertion and thebone marrow 14 fills the valleys between the lands. Occasionally, thenail may fracture as indicated at 29 in FIG. 1 and the broken portionsof the nail must then be removed. If not removed, the broken portions ofthe nail move relative to each other as the femur l flexes and the sharpjagged edges of the lands 18 and 20 at the fracture 29 engage the wallof the medulla 12 and cause pain and discomfort to the person.

The first step in removing the broken portions of the nail 16 consistsof providing an opening, now shown, to the medulla 12 in the upper orright-hand end, not shown, of the femur 10. The opening can be the sameas the original opening through which the nail 16 was inserted. Oncethis opening is provided, a conventional instrument, such as a Reynold'sDriver 30, has its shank 32 inserted through the opening into themedulla 12. A screw-threaded socket 34 at the lower end of the shank 32is then threaded onto the threaded part 28 of the upper or righthandbroken portion of the nail which is adjacent the opening. Thereafter theslidable weight 36 of the Driver is manually reciprocated along theshank 32. The intermittent engagement of the upper or right-hand end ofthe weight 36 with the rubber washer 37 and annular shoulder portion 38of the Driver gradually moves the broken upper or right-hand portion ofthe nail outwardly of the medulla 12. During this movement, thesharp-edged ribs 26 broach grooves in the wall of the medulla andprovide paths for the lands 18 and 20 of the center part 22. Normally,the lands l8 and 20 and the ribs 26 are partially embedded in themedulla wall if the nail has been inserted for a period of time.

The extractor of this invention is shown in detail in FIGS. 2 through 7of the drawings and generally includes an inner rod member 40 and anouter concentric tubular member 42. As shown in FIGS. 2 and 6, theright-hand end of the tubular member 42 is welded at 44 to the aperturedend wall 46 of a hollow open cylindrical housing designated 48. Theright-hand end of the rod member 40 extends through the opening in theend wall 46 and includes a square-shaped portion 50, FIG. 7, whichextends through a like-shaped bore 52 in a drum 54 which is rotatablyand slidably received in the housing 48. The one end wall 56 of thedrum, FIG. 6, seats against the shoulder between the square-shapedportion 50 and the remainder of the rod 40 and the other or right-handend wall 58 of the drum is engaged by a handle assembly 60 which isscrewed onto the threaded right-hand end 62 of rod member 40. Thus thedrum 54, the handle assembly 60 and the inner rod member 40 are movableas a unit relative to the housing 48 and outer member 42. The handleassembly 60 includes an annular handle member 64 having a knurled outersurface. A bore in the handle-member 64 receives a reduced diameterextension 66 of a mounting member 68 of the assembly, FIG. 6, withmembers 64 and 68 being pinned together at 70. A threaded portion 72 ofthe extension 68 extends outwardly of a recess or bore 73 of theassembly.

As shown in FIGS. 2 and 4, the other end of the outer member 42 isprovided with a pair of fingers 74 and the other end of the inner member40 is provided with a like pair of fingers 76. One finger 74 isrespective to one finger 76 to arrange the fingers in two respectivepairs. As can be seen in FIG. 2, the fingers 76 are radially offset fromthe member 40 so as to lie in the same cylindrical plane as the fingers74.

As shown in FIG. 5, each finger is provided with an axial bore 78 whichreceived a pin 80 of hardened steel. The bores 78 of each respectivepair of fingers 74 and 76 converge axially and circumferentially withrespect to each other remote from the free end of the fingers of themembers 40 and 42. Thus sharp-edged angular projecting portions 82 ofthe pins of each respective pair of fingers likewise converge axiallyand circumferentially of each other. The pins may be secured in anyconventional manner within the bores 78 such as by cementing or by theuse of pins 84 which extend laterally through aligned openings providedin the fingers and in the pins 80. The fingers 74 and 76 are of across-sectional shape so as to fit within the valleys between the lands18 and 20 as shown in FIG. 4.

Referring now to FIGS. 6 and 7, the open end of the housing 48 includesan enlarged annular rib 88 having a knurled outer surface anddiametrically opposite threaded bores 90 which receive the threadedinner ends 92 of a pair of knurled handles 94. The ends 92 extendinwardly of bores 90 and within an axially enlarged circumferentialgroove 96 of the drum 54. The alternate engagement of the spaced walls98 and 100 of the groove 96 with the ends 92 provide stops limitingaxial movement of the inner member 40, drum 54 and handle 60 relative tothe housing 46 and outer member 42.

As shown in FIG. 7, the drum 54 further includes an axial groove 102having a radially facing axially extending wall 104. The housing 48includes a shouldered boss 106 having an internally threaded portion108. The shouldered partially threaded shank 110 of a manually rotatablehandle 112 is threadedly received within the boss 106. The engagement ofthe semispherical end 114 of the handle 112 with the wall 104 uponrotation of handle 112 rotates the drum 54 and the inner member 40relative to the housing 48 and the outer member 42 and moves the fingers74 and 76 of each respective pair of fingers toward each other. Sincethe wall 104 is axially elongated, the inner member 40 and outer member42 may be rotated relative to each other at any relative axial positionthereof, such position, of course, being limited by the engagement ofthe ends 92 of handles 94 with walls 98 or 100.

After the right-hand or upper broken portion of the nail 16 has beenremoved, the members 40 and 42 of the extractor are inserted through theopening in the upper end of the femur into the medulla 12. Therespective pairs of fingers 74 and 76 are then located in diagonallyopposite valleys of the central part 18 of the remote broken portion ofthe nail as previously described and as shown in FIGS. 2 and 4. Thehandle 112 is then rotated to cause the end 114 to engage the wall 104and rotate the drum 54 and the inner member 40 relative to the housing46 and outer member 42 so that the sharp-edged portions 82 of the pins80 of respective pairs of fingers bite into the lands 18 and 20 of thenail and grip or clamp the other broken portion of the nail to theextractor. Thereafter a conventional instrument, such as a ReynoldsDriver, indicated schematically at 118 in FIG. 6 is threaded to portion72 of extension 66 and the manipulation of the ring weight of theinstrument draws the remote broken portion of the nail 16 outwardly ofthe medulla 12 through the opening in the upper end of the femur.

The extractor of this invention also includes an additional featurewhich is provided by an annular end anvil or abutment 120, FIG. 2,provided on the free end of the inner member 40 between the fingers 76.When the extractor is initially inserted into the medulla and thefingers 76 positioned in one diagonally opposite pair of valleys withthe aid of a fiuoroscope, the anvil 120 will be seated on the fracturedend of the remote broken portion of the nail. A conventional instrument,such as a Reynolds Driver, is thereafter attached to the handle assembly60 as previously described. By manipulation of the ring weight of theinstrument, the anvil 120 will shift the remote broken portion of thenail slightly to the left or axially inwardly of the medulla so as tocause the sharpedged ribs 26 to broach the wall of the cavity 12 andpermit easier removal of this broken portion of the nail.

In order to prevent possible damage to the instrument or to the lands 20and 22 of the nail, the handle 112 may be provided with a conventionaltorque-limiting clutch arrangement so that once a certain amount offorce is applied between the housing 48 and drum 50, continued rotationof the handle will cause slippage between the handle and the threadedportion 108 ofthe boss 106.

Thus this invention provides an improved extractor for removing a brokenportion of an intrarnedullary nail.

We claim:

1. An extractor for removing from a skeletal member cavity anintrarnedullary nail having a portion of generally cruciform crosssection comprising, in combination, a pair of annular telescopic androtatable members, each including a plurality of generally axiallyextending finger means at one end thereof arranged in respectiveannularly spaced pairs, each pair of finger means adapted to axiallyreceive a respective land of the nail therebetween, means for rotatingthe members relative to each other to move the finger means of eachrespective pair circumferentially toward each other to grip therespective nail land circumferentially therebetween, and means forapplying an axial force to the members to remove the gripped nail andmembers from the skeletal member cavity.

2. An extractor for removing from a skeletal member cavity anintrarnedullary nail having a portion of generally cruciform crosssection comprising, in combination, a pair of annular telescopic androtatable members, each including a plurality of generally axiallyextending fingers at one end thereof arranged in respective annularlyspaced pairs, each pair of fingers including coacting gripping meansadapted to axially receive a land of the nail therebetween, a radiallyfacing axially extending abutrnent on one member, means on the othermember engageable with the abutment for rotating the members relative toeach other to move the fingers of each respective pair toward each otherto move the gripping means into engagement with the nail land, and meansfor applying an axial force to the members to remove the gripped nailand members from the skeletal member cavity.

3. An extractor for removing from a skeletal member cavity anintrarnedullary nail of generally cruciform cross section having an endportion and a ribbed portion wedged into the cavity wall comprising, incombination, a pair of annular telescopic and rotatable members, meanson the end of one member engageable with the end portion of the nail toaxially shift the nail within the cavity and cause the ribbed portion tobroach the cavity wall and free itself therefrom, each member includinga plurality of generally axially extending finger means at the one endthereof arranged in respective annularly spaced pairs, each pair offinger means adapted to axially receive a land of the nail therebetween,means for rotating the members relative to each other to move the fingermeans of each respective pair toward each other to grip the nail landtherebetween, and means for applying an axial force to the members toremove the gripped nail and members from the skeletal member cavity.

4. An extractor for removing from a skeletal member cavity anintrarnedullary nail having a portion of generally cruciform crosssection comprising, in combination, a pair of annular telescopic androtatable members, each including a plurality of generally axiallyextending fingers at one end thereof arranged in respective annularlyspaced pairs, each respective pair of fingers being adapted to axiallyreceive a land of the nail therebetween, an axially extending grippingmember on each finger, the gripping member on respective pairs extendingaxially and circumferentially convergent to each other, means forrotating the members relative to each other to move the fingers of eachrespective pair toward each other and engage the gripping members withthe nail land therebetween, and means for applying an axial force to themembers in the axial direction of convergency of the gripping members tomember cavity.

i i i I

1. An extractor for removing from a skeletal member cavity anintramedullary nail having a portion of generally cruciform crosssection comprising, in combination, a pair of annular telescopic androtatable members, each including a plurality of generally axiallyextending finger means at one end thereof arranged in respectiveannularly spaced pairs, each pair of finger means adapted to axiallyreceive a respective land of the nail therebetween, means for rotatingthe members relative to each other to move the finger means of eachrespective pair circumferentially toward each other to grip therespective nail land circUmferentially therebetween, and means forapplying an axial force to the members to remove the gripped nail andmembers from the skeletal member cavity.
 2. An extractor for removingfrom a skeletal member cavity an intramedullary nail having a portion ofgenerally cruciform cross section comprising, in combination, a pair ofannular telescopic and rotatable members, each including a plurality ofgenerally axially extending fingers at one end thereof arranged inrespective annularly spaced pairs, each pair of fingers includingcoacting gripping means adapted to axially receive a land of the nailtherebetween, a radially facing axially extending abutment on onemember, means on the other member engageable with the abutment forrotating the members relative to each other to move the fingers of eachrespective pair toward each other to move the gripping means intoengagement with the nail land, and means for applying an axial force tothe members to remove the gripped nail and members from the skeletalmember cavity.
 3. An extractor for removing from a skeletal membercavity an intramedullary nail of generally cruciform cross sectionhaving an end portion and a ribbed portion wedged into the cavity wallcomprising, in combination, a pair of annular telescopic and rotatablemembers, means on the end of one member engageable with the end portionof the nail to axially shift the nail within the cavity and cause theribbed portion to broach the cavity wall and free itself therefrom, eachmember including a plurality of generally axially extending finger meansat the one end thereof arranged in respective annularly spaced pairs,each pair of finger means adapted to axially receive a land of the nailtherebetween, means for rotating the members relative to each other tomove the finger means of each respective pair toward each other to gripthe nail land therebetween, and means for applying an axial force to themembers to remove the gripped nail and members from the skeletal membercavity.
 4. An extractor for removing from a skeletal member cavity anintramedullary nail having a portion of generally cruciform crosssection comprising, in combination, a pair of annular telescopic androtatable members, each including a plurality of generally axiallyextending fingers at one end thereof arranged in respective annularlyspaced pairs, each respective pair of fingers being adapted to axiallyreceive a land of the nail therebetween, an axially extending grippingmember on each finger, the gripping member on respective pairs extendingaxially and circumferentially convergent to each other, means forrotating the members relative to each other to move the fingers of eachrespective pair toward each other and engage the gripping members withthe nail land therebetween, and means for applying an axial force to themembers in the axial direction of convergency of the gripping members toremove the gripped nail and members from the skeletal member cavity.